US President Barack Obama named a Goldman Sachs executive and large campaign contributor as ambassador to Canada on Thursday amid potential rifts between the allies over the Keystone pipeline.

Bruce Heyman, managing director for private wealth management at the investment bank, lives in Obama's base of Chicago and is a so-called "bundler" who raised funds for the president's campaigns.

In a statement announcing Heyman and nominees for unrelated posts, Obama called them "experienced and committed individuals." Heyman requires confirmation by the Senate.

Early reports of Heyman's potential nomination -- and the present absence of an ambassador in Ottawa -- triggered criticism in the Canadian press, which asked if Obama was putting sufficient priority on the neighbor and ally.

The previous ambassador, Chicago-based corporate lawyer David Jacobson, left Canada in July.

Like previous presidents, Obama has regularly named prominent fundraisers to diplomatic posts, seen as one of the top rewards doled out to campaign supporters.

The nomination process has increasingly taken longer, particularly with wealthy candidates, as aides review their finances for potential scandals.

The Senate generally approves political appointees as ambassadors, although Heyman will likely face questions from Obama's rival Republican Party over the controversial Keystone XL pipeline.

Obama has not made a decision on whether to approve construction of a 1,179-mile (1,897-kilometer) section of the pipeline to stretch from Alberta to Nebraska.

Canadian Prime Minister Stephen Harper's government has led a public relations campaign to win approval for the pipeline, which Republican lawmakers say will create jobs.

Environmentalists worry that the downsides outweigh any benefits as oil from Canada's tar sands is intense in carbon responsible for climate change and a pipeline break would pollute groundwater.